1. Field of the Invention
The present invention relates to a continuous carbon fiber/thermoplastic resin fiber composite yarn and a method for manufacturing the same. More particularly, the present invention relates to a continuous carbon fiber/thermoplastic resin fiber composite yarn having excellent mechanical properties, being light in weight, and having excellent moldability and impregnating ability by including a continuous carbon fiber and a thermoplastic resin fiber.
2. Description of the Related Art
In view of the environmental impact of transportation means such as automobiles and aircraft, reduction in the amount of energy consumed and the amount of carbon dioxide emitted is required. Further, improvement in fuel efficiency is required through the use of light weight components. As such, numerous studies have been conducted on the development of a composite material for automobiles which includes carbon fiber for implementing light weight properties.
Carbon fiber is an advanced material that weighs about 80 percent less and is 10 times stronger than steel, and has much higher tensile strength, tensile modulus, and the like compared with other fibers and further has excellent specific strength and specific modulus. As such, carbon fiber is appropriate for use as a reinforcing material of a composite material. Further, since carbon fiber has excellent heat resistance, chemical stability, electrical conductivity, flexibility, and the like, a variety of applications are available in various fields such as not only aerospace, aviation, wind power generation, and sports and leisure industry, but also medical and construction. Further, a carbon fiber having excellent interfacial adhesion is a material that may be used as a main material in a polymer composite material.
In a polymer composite material of carbon fiber, a carbon fiber/thermoset resin composite material has a disadvantage in that a product needs to be manufactured by molding at one time, and a further disadvantage in that there is a restriction on maintenance and recycling because the carbon fiber/thermoset resin composite material has a three-dimensional crosslinked network structure in which the material does not dissolve after being cured. A carbon fiber/thermoplastic resin composite material is advantageous in that the material provides high toughness, high-speed moldability, easy post-processability, recyclability, and the like. However, a carbon fiber/thermoplastic resin composite material has a disadvantage in that the resin has high viscosity and it is difficult to impregnate the thermoplastic resin into the carbon fiber. In order to solve the aforementioned problem, it is necessary to develop a carbon fiber/thermoplastic resin composite material and a manufacturing technology thereof.
In general, in the case of a carbon fiber, it is difficult to form a tow composed of bundles from 3,000 strands to 320,000 strands of a carbon fiber having a diameter of about 7 micrometers and to obtain an interlacing in which thermoplastic resin fibers are mixed together between carbon staple fibers of the tow.
In order to solve the aforementioned problem, a process illustrated in FIG. 1 has been used in the related art. FIG. 1 is a schematic view of a process by which a composite yarn in the related art is manufactured. More specifically, a composite yarn 12 has been manufactured by interlacing a glass fiber 10 having a continuous fiber form with a thermoplastic resin fiber 11. Alternatively, a composite yarn 12 has been manufactured by interlacing a carbon staple fiber 13 with a thermoplastic resin fiber 11. The composite yarn 12 manufactured from the glass fiber 10 and the thermoplastic resin fiber 11 is disadvantageous in that it has a higher specific weight and lower strength than a composite yarn manufactured from a carbon fiber. In addition, the composite yarn 12 manufactured from the carbon staple fiber 13 and the thermoplastic resin fiber 11 is disadvantageous in that it has lower physical properties than a composite yarn manufactured from a continuous carbon fiber having a continuous fiber form in carbon fiber.